Active and Passive Cell Balancing Techniques for Li-Ion Batteries used in EVs

This paper provides the importance of batteries for EVs and the various performance parameters. Passive Cell balancing technique and active cell balancing for batteries is discussed. In batteries we have a protection system for overcharging and over discharging. When a stack of cells is present, where each cell has different SoC compared to the other and the cell with least SoC results in activating the over discharge protection of the system. Similarly, the cell with over charge will activate the overcharging protection scheme which is undesirable and may lead to maloperation of the battery. These can be addressed and for a proper function of the battery pack, Cell Balancing system is very much essential. There are different types of cell balancing schemes and, in this work, we have addressed about one of the simple and reliable schemes of cell balancing ie., Passive cell balancing and its operation is simulated. A hardware prototype is built using Arduino IDE for switched shunt resistor passive cell balancing techniques and also in the aspect of active cell balancing Flyback converter-based cell balancing system (Open Loop) is simulated, the simulation results are presented in MATLAB.